1. Field of the Invention
The present invention relates to a method for disposing of waste water containing emulsified oil.
2. Description of the Prior Art
Lubricating oil is frequently used in processes of working metals such as rolling, wire rod drawing, cutting, drilling, surface finishing, etc. The present invention relates to the disposal of oil containing emulsified waste water (emulsion waste liquid) which has been considered impossible to dispose of by known technique of separation by specific gravity differences or the like.
The disposal of oil containing emulsified waste water is thus a very important problem from the viewpoint of preventing environmental pollution.
Hitherto an oil containing emulsified waste water, for example, resulting from metal working processes, has been disposed of by separating the oil and water present in the oil containing emulsified waste water after breaking the emulsion with certain means, as disclosed in the report entitled "Effluent treatment of emulsion cleaners" (Metal Finishing Journal 18 (12), pp. 385 - 388 (1972).
However, conventional processes for disposing of such waste liquid comprise the step of independently breaking the emulsion, which decreases the efficiency of the system considerably and leads to high cost.